Carburetor



Aug. 15. 1933.

L. DE MARCO CARBURETOR Filed May 20, 1932 3 Sheets-Sheet 1 4 wuw/tw-LOU/5 DKNHRL'O ATTORNEY Aug. 15, 1933. DE MARCQ 1,922,569

CARBURETOR Filed May 20. 1932 3 Sheets-Sheet 2 INVENTOR LOU/5 ZEN/7R ['0ATTO RN EY L. DE MARCO Aug 15, 1933.

CARBURETOR Filed May 20, 1932 3 Sheets-Sheet 3 (a a A: a 2 3 2.

H I 1 m5 b llllLl Fla. 9

INVENTOR LOU/5 HEM IPZW ATTORNEY :Patented Aug. 15, 1933 1,922,569

UNITED STATES PATENT OFF-ICE 1,922;569 CARBURETOR Louis De Marco,'Cleveland,'()hio, 'assignor of giiteen per centto Percy A.Sewn-Cleveland,

Application 'May 20,1932. Serial No. 612,534

' "6 Claims. (01. 261-52) This invention relates in general tocarburetors tial control is necessary while the engine is runforautomobiles and other internalcombustion ning' under conditiona wherecomparatively little engines which carburetors effect vaporization ofpower is required and the suction of the engine-is gasoline or otherfuels and themixing of the Substantial.

- '95 vaporized'fuel with a suitable amountof air to With these "andother objects in view'the inso obt in hi h p explosions the cylindersofvention consists in theconstruction andnovcl the engine, and moreparticularly to suction carcombination of partsfully describedhereinafter, buretors such as extensively usedfor automoillustrated, int e a p y d w bile engines. It is well known that the best re-- pointedout in the claims appended hereto, it

lt are Obtained h th tions' of fuel being understood that variouschanges in the c;

and-air in the mixture are such'that complete for proportion, size andminor details of combustion of all the gasoline in the mixture structon-w'it i th D 'OTYCIHJimS, y-

takes'place attheproper time leaving no 1111- sorted to withoutdeparting from the spirit of burned parts to be wasted. It is also wellknown e ve t Ofithat this desirable result is difficult of attain- Inthe drawing w plified form 70 ment with suction type of carburetors.*Thus, O a Carburetor embodying the inventifln! when theispeedof'fheiengineincreases th Figure lis a side elevation of a-carburetoraction produced increases inpropoition- Increased w it g the invention;suctionproportionallyincreases theamount of -F u1' isa longitudinalvertical Section view 26 gasoline sucked from the gas nozzle of thecarhr h the carburotorshown in Figurel;

buretor. On the other handg increased' suction v Figure 3 is a SectionalView On 01 does notproportionally 'increase the amountof Figure airpassing through the air passage and conse- Figure 4 is a sectional viewon line 4 4' ofFig- V quently, at the" higher speeds of thee-rigineythei 7 25 i t r 111 be t h gasonne e nd Figure 5 is a sectional view online 55- ofFig- 90 therefore much waste, accumulatibnof'caibon, lire linterference with the proper lubrication of the Figures 6, 7, 9 Shawdiaglammatical Views cylinder walls, and'fouling of spark plugs will. ofthe positions of the valves the throttle valve occur. I Y a i and theair intake control valveat difierentspeeds When drivingat'm'ediumspeeds, say coasting h enginevThus $5 range,'or'whileigoing downhill'cor'nparatively Figure 6 ShOWSthe Starting position of Saidlittlepower is needed. "Under-such conditions valve economy:- and smoothperformance of the engine Figure the medium Speed position of Said ca-llfor a'rather'leanmixture, whereas, hard valves;

pulling of the engine at low speedsfor {instance F gu e ii' highspeediposition of said a v 90 while climbing a hill, must be met witha-slightly and richer mixture. Figure 9 the high power position of saidvalves The primary object of the present invention'is 'at relat v l lowp to provide means for controllingthe amount of W q p of Carburetor Aillustrated 40 :airdrawn into the mixture chambersothatthe hereinembodies three main parts, the gasoline proper mount 0fair:wi11.beautomatically "fed orfloat chamber B; the barrel or mixing chamberinto'the carburetor and mixe'dwith-the gas 'to C and the air intake D.The carburetor A is form the gas and air mixture-most efficientunderspli h i y as t thus p v in n pp r the'existing conditions of speedetc.part 3 which forms a cover member for float 7 Aiurther object ofthe:inventionisto provide chamber B arranged in a lower part 4. A-floata valve: arranged inthe air intake of the carbu- 5 within chamberBhingedly attached to upper rotor and controlled by the suction of theengine, part3, as at controls the movements of needle for'reeding acorrespondingly increased volume valve 6 in inlet passage 7 of a valvebody 8 for of'air into the mixing chamberwhen the suction maintainingthe gasoline in chamber B at a preof the engine increases.determinedlevel. An inlet passage 9 adjacent a A: still further objectof the invention is to conremovable strainer 10 and in communicationwith plc the automatically actuated control' of the a fuel container notshown feeds gasoline into valve in the air intakelwiththe throttle valveof passage 7, from whence it'flows into chamber B thecarburetortoeffectpartial control of the whenever the float 5 drops suificiently to openvalveinthe air intake by the throttle. .Such parvalve 6. 10

Float chamber B communicates with the barrel or mixing chamber C,through a spray nozzle 11 threadedly secured within and extendingthrough a passage 12 formed in the lower part 4 of the carburetor.Nozzle 11 is formed with a lateral passage 15 adjacent its lower end inalinement with and forming a continuation of a short passage 1'? formedin the bottom wall of chamber B.

The desired charge of gas will thus be sucked from chamber B throughpassages 17 and 15 and thence out through the central opening 16 innozzle 11 into mixing chamber C. The customary idling jet 2o also drawsfuel from chamber B upwardly and discharges into barrel chamber Cthrough port 21 arranged with its outlet end adjacent the edge of thecommon butterfly throttle 22, so that it operates only when saidthrottle is slightly opened.

An air intake D communicating with barrel chamber C furnishes thenecessary air, when the suction of the engine creates a vacuum in barrelchamber C, and a vacuum controlled air valve 23 of common butterfly typecontrols the amount of air flow. Valve 23 is actuated by a piston 24arranged within a cylinder 25, on upper part 3 of carburetor A. Thiscylinder communicates through passage 26 with barrel chamber-C justabove butterfly throttle 22 for continuous exposure to the suction ofthe engine. A downwardly extending piston rod 27 on piston 24 andpreferably integrally formed therewith is guided in a longitudinallyslotted sleeve on-extension 28 of cylinder 25 and this piston rod iscoupled with valve 23. Thus piston rod 27 is slotted at 29 forengagement with a lever 30 pivotally mounted on shaft 31 of air valve 23and yieldingly secured thereto by means of a spring 33 attached at one 7end to an extending arm 34 of said lever and at its otherend to a clamp51 rigidly secured to the shaft '31, to permit of slight relativemovement of lever 30 with respect to shaft 31 for a purpose later to bedescribed. The free end 35 of lever 30 is formed with a flat circularenlargement 36 which extends through slots 3'7 in extension 28 ofcylinder 25 and thence into slot 29 for actuation during shifting ofpiston 24 and its piston rod 27 Piston 24 is yieldingly forced in adownward direction by means of a compression spring 38 arranged withincylinder 25 and seated between piston 24 and the top wall 39 of saidcylinder, a

sleeve likemember 40 serving as a guide for the spring to preventbuckling when under compression.

The automatic actuation of air valve 23 by the suction of the engine ispartially limited by throttle valve 22 to prevent unrestricted openingof air valve 23, except when valve 22 is fully open. Thus a lever 43rigidly attached to shaft 41 of throttle valve 22 is pivotally connectedto a lever 45 by means of a connecting rod 33, the free end of lever 45being in turn pivotally connected to the part A of the carburetor. Lever45 is formed with a bifurcated outer end 49 which slidably embraces thepiston rod 27, the latter being provided with a flange 48 at its lowerend for limiting the upward movement of piston 24, when the forkedshaped end 49 of the lever 45' engages with flange 43. It will of coursebe understood that a manually operated choke valve is unnecessarybecause of the automatic choking action of the carburetor.

When a very rich mixture is desirable, as in starting a cold engine, thethrottle valve is slidably opened manually, whereas the air valve willof the engine so that spring 38 can force piston sequently the mixturedecreases in richness, due

to the admission of an ample supply of air, see the diagram shown inFigure 7, which shows driving at medium speeds or on a smooth road wherecomparatively little power is needed, and the engine suction isrelatively high.

When full power is desired, the throttle valve 22 is fully opened. Thiswill raise lever 45 to the position shown in the diagram of Figures 8and 9 thus permitting the full opening of air valve 23 and also theclosing of air valve 23 when the suction of the engine materiallydecreases. Assuming the engine is going at high speed with fully openedthrottle, then the suction of the engine is so high that piston 24 willbe fully raised and air valve 23 fully opened (see Figure 8). Decreaseof engine speed for instance while climbing a hill with fully openedthrottle valve materially decreases the suction 24 downward and thuspartly close the air valve 23. This action automatically increases therichness of the mixture at a time when most needed, a diagram showingthe relative position of throttle valve 22 and air valve 23 underconditions just recited is shown in Figure 9.

The yielding connection of air valve 23 with lever 30 permits relativerotation between shaft 31 of valve 23 and lever 30 and thus preventsdamage or breakage of lever 30 by backfiring.

Throttle valve 22 is actuated as customary by a push and pull element(not shown) ordinarily mounted on the steering gear or instrument boardof the automobile. A wire connection also not shown interconnects said,push and pull element with the operating lever 42 on shaft 41 ofthrottle valve 22,

Having thus described my invention:

What I claim is:

1. A carburetor comprising a body, mixing and fuel chambers in saidbody, a nozzle in the mixing chamber, a throttle valve in said mixingchamber, an air intake chamber, a valve in said air intake chamber,means to yieldingly hold said .latter valve in closedposition, meansadapted to open said latter valve according to the speed of the engineand means for limiting opening of said latter valve according to theposition of said throttle valve.

2. In a carburetor a throttle valve and a valve controlling the airintake, means to open said latter valve according to the speed of theengine, and coupling means between said throttle valve and said othervalve for limiting the opening of said other valve to definite positionsin accordance with the opening of said throttle valve.

3. In a carburetor a throttle valve and a valve controlling the airintake, means to open said latter valve according to the suction of theengine, and coupling means between said throttle valve and said othervalve and preventing full opening of said other valve unless saidthrottle valve is sufliciently opened.

4. In a carburetor a throttle valve and a valve controlling the airintake, a cylinder communieating with the intake side of the engine, apiston within said cylinder coupled with said air controlling valve,means to yieldingly close said latter valve, and means coupling saidthrottle valve with said air controlling valve and preventing Iullopening of said air controlling valve unless said throttle valve issufiiciently opened.

5. In a carburetor a throttle valve and a valve controlling the airintake, a cylinder communieating with the intake side of the engine, apiston within said cylinder having an extension coupled with said aircontrolling valve, a lever pivotally mounted on said carburetorconnected with said piston and .means on said extension of said pistoncooperating with said lever to limit the upward movement of said pistonand therewith the opening of said air controlling valve unless saidthrottle valve is sufficiently opened.

6. In a carburetor, a throttle valve, a valve controlling the airintake, a cylinder communicating with the intake side of the engine, apiston within said cylinder having a slotted extension, ,a lever coupledwith said air controlling valve and slidably interengaged with saidslotted extension of said piston and means coupled with said throttlevalve and slidably interengaged with said extension of said piston forlimiting the operation of said air valve by said piston in accordancewith the position of said throttle valve.

LOUIS DE MARCO.

